I would recommend getting a piece of 20 gauge stainless steel music wire, eighteen inches long. Bring the ends together/parallel and clamp very tight with a pair of vice grips. You should now have a loop with no defined other end. (as yet) Place a 12 penny nail or equivalent into a secured vice. Now place the wire loop over this nail/pin. Pull on the vice-grips to straighten out the wire. The end goal here, is to end up with an eye at the nail/pin end with the wires close together below that. When this is complete, then fold over the two free ends 180* about 1/2", and then wrap with friction tape, to form a handle.

The aluminum finger-trapping fids are available from some guy on the East Coast. Dave DeWolf will cheerfully share the name and address of that finger-trapping fool. Alternately, you can make your own finger-trapping wires. Start with music wire or aircraft safety wire. Apparently music wire is the best, but I use aircraft lock wire because it is free from my friendly neighborhood aircraft mechanic. Use 20/1000 for Cypres cord, 30/1000 or 32/1000 for most suspension lines and 40/1000 for thick Dacron steering lines.

I half hitched my finger while releasing my brake lines and had it trapped tight against the ring . The pain was unbelievable to the point where i thought i was going to loose the top portion of my finger, I reached up with the other hand above the ring and pulled down enough to release the pressure and remove my finger, Now that is what i call a "finger trap" !